rootsRemoved

Called by indexing infrastructure to notify indexer that roots were deregistered,
for example the project owning these roots was closed. The indexer may free memory caches
for given roots or do any other clean up.

getIndexerName

Return the name of this indexer. This name should be unique because the infrastructure
will use this name to produce a separate data directory for each indexer
where it has its own storage.

Returns:

The indexer name. This does not need to be localized since it is
never shown to the user, but should contain filesystem safe characters.

getIndexVersion

public abstract int getIndexVersion()

Return the version stamp of the schema that is currently being stored
by this indexer. Along with the index name this string will be used to
create a unique data directory for the database.
Whenever you incompatibly change what is stored by the indexer,
update the version stamp.